What is a larvicide?

• A. A larvicide is a pesticide that kills mosquito larvae and is registered with the U.S. Environmental Protection Agency for that use.
• B. A larvicide is a product used to kill adult mosquitoes.
• C. A larvicide is a device that traps larvae.
• D. A larvicide is a fertilizer used in larval habitats.

Answer: (A)

A larvicide is a pesticide formulated and registered with the U.S. Environmental Protection Agency specifically to kill mosquito larvae in water. It targets the immature stage, stopping mosquitoes before they become biting adults. Because it must be EPA-registered for this use, it’s deployed in larval habitats such as standing water to reduce the mosquito population at its source. Examples include products containing Bacillus thuringiensis israelensis (Bti) or Bacillus sphaericus, and insect growth regulators like methoprene that prevent larvae from maturing.

Killing adults is not a larvicide—those products are adulticides. A device that traps larvae isn’t a pesticide, and a fertilizer used in larval habitats isn’t a pesticide either.